This invention is related to apparatus and methods for positioning and puncturing an artery preparatory to the insertion of a needle or catheter therein.
There are many situations which arise in medical practice, such as insertion of a catheter and withdrawal of blood, which require the puncturing of an artery with a needle or other similar device. Even experienced medical personnel sometimes have difficulty in positioning and puncturing an artery in some patients. It is particularly difficult to locate and puncture an artery in a patient who is obese because the arteries of such a person are not as close to the skin surfaces as the arteries in a person of normal weight. It is also often very difficult to locate and puncture an artery in a person who has very low blood pressure, which often occurs in persons who are extremely ill. Human arteries are normally two to eight millimeters in diameter; and some arteries may be difficult to locate even in a healthy person.
Prior methods for puncturing an artery include only means for determining the approximate position of the artery. Even after a medically trained person has found the patient's artery, puncturing the artery may be difficult, requiring more than one penetration of the patient's skin. In addition, difficulties are often encountered after the artery has been located since the insertion of the needle can cause the artery to roll away or be displaced as the surrounding body tissue is displaced.
Similar problems also arise when medical personnel attempt to locate and puncture a vein. Prior methods only allow medical personnel to determine the approximate location of a vein. Insertion of a needle or catheter can also cause the vein to roll away.
Therefore, there is a need in the art of medical instrumentation for a device which accurately identifies the location of a patient's artery or vein and which retains the artery or vein in position for puncturing.